Recent evidence suggests that the learning processes that underlie the acquisition of goal-directed actions and that support their transition into habits are encoded within distinct regions of the dorsal striatum and involve distinct cortio-striatal networks. Disorders of `voluntary' movement, e.g. Parkinson's disease, and involving intrusive involuntary movement, e.g. Tourette's syndrome, obsessive compulsive disorder and Huntingdon's disease, have also been found to involve damage to cortico-striatal networks and to result in severe cognitive deficits in choice, planning and executive processes generally. These cases make it clear that the capacity for goal-directed action is highly adaptive. Nevertheless, although research into the physiological systems that subserve learning processes in humans and other animals has been of ongoing concern to the neuroscience research community, the neural bases of both goal-directed and habit learning are still very poorly understood. The broad, long-term objective of the current project is, therefore, to understand the neural systems that control both goal-directed and habitual learning processes. In this project we will focus specifically on cortio-striatal networks involving the medial prefrontal cortex and its efferents to the dorsomedial striatum in goal-directed learning and sensorimotor cortex and its afferents to dorsolateral striatum in habit learning under three specific aims: (i) to examine the role of the dorsomedial striatum in goal-directed learning processes; (ii) to explore the role of cortico-dorsomedial striatal circuits in goal-directed learning; and (iii) to compare the role of dorsomedial and dorsolateral striatum in actions and habits. We plan to use behavioral manipulations and tests that allow direct assessment of the specific learning processes engaged under a number of circumstances and to establish the neural networks that support these learning processes using a series of molecular and cellular markers and interventions that, in recent years, have proven to be of value in studying neural circuits and systems. PUBLIC HEALTH RELEVANCE The learning processes that underlie the acquisition of goal-directed actions and that support their transition into habits are encoded within distinct regions of the dorsal striatum and involve distinct cortio-striatal networks. Disorders of `voluntary' movement, e.g. Parkinson's disease, and involving intrusive involuntary movement, e.g. Tourette's syndrome, obsessive compulsive disorder and Huntingdon's disease, have also been found to involve damage to cortico-striatal networks and to result in severe cognitive deficits in choice, planning and executive processes generally. These cases make it clear that the capacity for goal-directed action is highly adaptive. Nevertheless, the neural bases of both goal-directed and habit learning are still very poorly understood. The broad, long-term objective of the current project is, therefore, to understand the neural systems that control both goal-directed and habitual learning processes. In this project we will focus specifically on cortio-striatal networks involving the medial prefrontal cortex and the dorsomedial striatum in goal-directed learning and sensorimotor cortex and its afferents to dorsolateral striatum in habit learning. We plan to use behavioral manipulations and tests that allow direct assessment of the specific learning processes engaged under a number of circumstances and to establish the neural networks that support these learning processes using molecular and cellular approaches that have proven of value in studying neural circuits and systems.